Pulse width modulation (PWM) systems can be used to generate analog signals from digital data. In some instances, PWM signals are used to drive H-Bridge circuits or other output amplifiers to achieve high power and high efficiency amplification. One particular PWM modulation technique is sometimes referred to as a BD modulation technique. In BD modulation, the content is modulated into a B-PWM signal and a D-PWM signal, and the content is recovered by subtracting the B and D signals.
If the PWM driver circuit provides the BD PWM signal as a pure digital signal with very fast edges, the BD PWM signal has very short propagation times and good distortion performance. Such a signal also provides relatively low “shoot through current”. Further, a pure digital PWM driver circuit has relatively low power consumption. Unfortunately, the fast transitions generate strong electromagnetic interference (EMI). While it is possible to improve the EMI performance by using slow slew-rate-controlled edges without penalizing the total harmonic distortion, the slew-rate controlled edges include an additional challenge of controlling the “shoot through current” and requires the use of an analog pre-driver circuit, both of which increase the overall power consumption of the circuit.